1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatus, and products for network address assignment in a data center.
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
One area of computer systems that has seen improvements is the area of data communications among computer systems. Standards for data communications are evolving constantly. Today, for example, the primary protocol for data communications amongst computer systems is IPv4. IPv4 (Internet Protocol version four) is the fourth revision in the development of the Internet Protocol (IP) and it is the first version of the protocol to be widely deployed. At present, IPv4 is at the core of standards-based internetworking methods of the Internet and other data communications networks. IPv4 is still by far the most widely deployed Internet Layer protocol. IPv4 is described in IETF publication RFC 791 (September 1981), replacing an earlier definition (RFC 760, January 1980). IPv4 is a connectionless protocol for use on packet-switched Link Layer networks (e.g., Ethernet). IPv4 operates on a best effort delivery model, in that packets are not guaranteed delivery, nor does IPv4 assure proper sequencing, or avoid duplicate delivery. These aspects, including data integrity, are addressed by an upper layer transport protocol (e.g., Transmission Control Protocol).
This data communications protocol, however, is advancing. A new protocol, called IPv6, has been standardized and will likely be the primary protocol for data communications for years to come. IPv6 (Internet Protocol version six) is the next-generation IP version designated as the successor to IPv4. IPv6 was defined in December 1998 by the Internet Engineering Task Force (IETF) with the publication of an Internet standard specification, RFC 2460. IPv6 is an Internet Layer protocol for packet-switched internetworks. The main driving force for the redesign of the Internet Protocol is IPv4 address exhaustion. IPv6 has a vastly larger address space than IPv4. This results from the use of a 128-bit address, whereas IPv4 uses only 32 bits. The new address space thus supports 2128 (about 3.4×1038) addresses. IPv6 also implements new features that simplify aspects of address assignment (stateless address auto-configuration) and network renumbering (prefix and router announcements) when changing Internet connectivity providers.
Although IPv6 is the future standard for data communications protocols, many computer systems today are not configured to operate in accordance with the IPv6 data communications protocol and, as such, typically cannot take advantage of many of the advancements provided by the new standard, such as self-assignment of network addresses. In many typical data centers containing large numbers of server chassis, for example, service processors of servers installed in the chassis are configured only for communication via IPv4 rather than IPv6. In such a data center, if no DHCP server is available to assign IPv4 network addresses, many communications problems may occur such as, for example, entire lack of communications amongst the service processor or network address conflicts (duplicate addresses). More specifically, in some data centers, service processors are configured to attempt to obtain a network address from a DHCP server for two minutes. If no network address is obtained from a DHCP server (the server is unavailable), the service processors are configured to default to a static IP address. Here, network address conflicts arise immediately amongst the service processors. Although IPv6 provides means by which a computing device may obtain an IPv6 address without the need of a DHCP server, reconfiguring many thousands of service processors to operate in accordance with IPv6 is costly and time consuming.